下穿既有建筑物暗挖地铁隧道围岩及地表变形规律研究

发布时间：2018-01-09 06:33

本文关键词：下穿既有建筑物暗挖地铁隧道围岩及地表变形规律研究　出处：《西安科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：开展黄土地区浅埋暗挖地铁隧道下穿既有建筑物施工诱发的围岩及地表变形规律研究具有重要价值。本文依托西安地铁4号线某浅埋暗挖地铁区间隧道工程,采用理论分析、数值模拟与现场监测相结合的方法进行研究工作,主要结论有:(1)分析黄土地铁隧道下穿既有建筑物矿山法施工的地表及建筑物沉降主要因素包括:工程地质条件、建筑物基础类型、建筑物与隧道洞身的水平距离和竖直距离等。分析黄土地铁隧道围岩变形主要因素包括:隧道所处地层黄土物理力学特性、开挖断面尺寸、隧道埋深、隧道开挖方法、地层损失、施工组织管理。对地层变形机理进行分析。(2)以西安地铁4号线某暗挖区间隧道为工程依托,采用FLAC3D软件建立下穿既有建筑的黄土地铁隧道三维计算模型,对暗挖区间隧道可行的CD法、CRD法和上下台阶法等三种施工工法诱发的围岩及地表变形规律进行仿真预测。结果表明,CRD工法施工在控制围岩变形、地表及建筑物沉降上,效果最佳,CD工法次之,上下台阶预留核心土法诱发的地表及建筑物沉降最大。提出了下穿既有建筑物暗挖区间隧道矿山法施工采用CRD工法进行施工的建议。(3)FLAC分析表明,隧道正穿既有建筑物施工对建筑物的竖向沉降影响较大,建筑物的差异沉降较小,旁穿既有建筑物隧道施工后的建筑物的变形较小,但是引起的建筑物差异沉降较大,建筑物易发生不均匀沉降。下穿既有建筑物浅埋地铁隧道暗挖施工引起的围岩变形规律演化过程经历了缓慢增长、急剧变形、基本稳定三个阶段。提出了暗挖地铁隧道地层加固措施并进行了 FLAC分析,表明提出的采取加固措施的CRD工法可以保证隧道安全下穿既有建筑物。(4)制定了隧道矿山法施工降水方案、地表以及建筑物的沉降变形监测方案。实践表明,提出的暗挖隧道采用CRD工法施工后的围岩变形、地表及建筑物沉降均在可控范围内,监测值与FLAC预测值基本吻合。
[Abstract]:In loess area of Shallow Metro Tunnel under has important value in research on deformation of surrounding rock and surface construction of buildings. This paper induced by relying on the Xi'an subway line 4 subway tunnel engineering, using theoretical analysis, numerical simulation and field monitoring method in combination with the research work, the main conclusions are: (1) analysis of loess subway tunnel under the main factors including the surface subsidence and building mine construction method: engineering geological conditions, type of building foundation, the building and the tunnel's horizontal and vertical distance. Including the analysis of surrounding rock of loess subway tunnel deformation factors: physical and mechanical properties of the strata at the loess tunnel the excavation, section size, tunnel depth, tunnel excavation method, ground loss, construction organization and management. The stratum deformation mechanism was analyzed. (2) in Xi'an Metro Line 4 A tunnel based on the project, using FLAC3D software to establish the crossing under the existing subway tunnel in Loess three-dimensional model building, the CD tunnel is feasible, this paper simulated the rules of deformation and surface CRD method and step method of three kinds of construction methods induced. The results show that the CRD method in the construction control surrounding rock deformation, surface subsidence and effect on buildings, the best, CD method of ground and building on the bench reservation core soil settlement induced by maximum is proposed. Through existing construction by using the CRD method of construction building the tunnel mining method is proposed. FLAC analysis showed that, (3) the tunnel is in both the vertical construction of buildings on building settlement influence, building the differential settlement is small, alongside a smaller deformation of existing buildings after the tunnel construction of the building, but the building caused by the difference The settlement of large buildings prone to uneven settlement. Beneath the existing building deformation law of surrounding rock of shallow buried subway tunnel caused by excavation construction of evolution has experienced slow growth, sharp deformation, the basic stability of three stages is proposed. The metro tunnel reinforcement measures and the FLAC analysis shows that the proposed by CRD method of reinforcing measures can ensure the safety of the tunnel beneath the existing buildings. (4) developed a mine tunnel construction dewatering scheme, and surface subsidence deformation monitoring scheme. Practice shows that the tunnel surrounding rock deformation by CRD construction method of ground and building settlement is in the controllable range, the value of monitoring and FLAC prediction value basically.

【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U451.2

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